A robot for cleaning a swimming pool pumps the water in its vicinity through a filter and then expels clean water out into the pool. A more advanced robot of this type utilizes the reaction force of the flow of the water being expelled to couple the robot itself to the floor and walls of the pool on which the robot is propelled, this coupling force assisting the propulsion of the robot along inclined or upright pool walls for cleaning purposes.
Since the effectiveness of the coupling of the robot to the floor and walls of the pool is a function of the reaction force of the flow of water expelled from the robot, and since this flow passes through the filter, the effectiveness of the robot's cleaning capability subsides as the filter becomes clogged. Specifically, the degree to which the robot clings to the floor or walls of the pool decreases as the filter becomes clogged, resulting in unsatisfactory cleaning.